Apparatus for preparing pressure gases



March 14, 1933. c. w. P. HEYLANDT APPARATUS FOR PREPARING PRESSURE GASESOriginal Filed Oct. 5, 1927 INVENTOR W A'lToRN Yfi Patented Mar. 14,1933 crmrs'rmn WILHELM PAUL HEYLANDT, or BERLIN-BRITZ, GERMANY,ASSlIGNOR T FL'U'GA AKTIENGESELLSCHAFT, OF ST. MORITZ, SWITZERLAND,CORPORATION-OI SWITZERLAND APPARATUS FOR PREPARING- PRESSURE GASESOriginal application flied October 5, 1927, Serial No. 224,268. Dividedand this application illed June 8,

1932. Serial The present invention relates to apparatus for containingliquefied gases of a character which is adapted to supply the same inthe gas-phase at different desired pressures. The invention has for itsobject generally an improved arrangement for gasifying liquefied gasesin their containers in a quick and expeditious manner with relativelysmall losses caused by heat leakage and the like.

More specifically, it is an object of the invention to provide acontainer for liquefied gas having draw-off connections which are soarranged with reference to their environment and the walls of thecontainer that a relatively small amount of heat is transferred from theoutside to the liquid in the container.

A further object of the invention is to provide a container of thecharacter indicated which is provided with inner and outervesselsconstructed of a material in which the expansion does not varyappreciably even at the lowest temperatures.

A still further object of the invention is to provide a container of thecharacter indicated, with internal means for conserving therefrigerating efi'ect of the gas which may be withdrawn or evaporatedwithin the container.

features of construction, combination of elements, and arrangement ofparts, which will be exemplified in the construction hereinafter setforth and the scope of the application of Which will be indicated in theclaims.

For a fuller understanding of the nature and objects of the invention,reference should be had to the following detailed description taken inconnection with the accompanying drawing, in which:

Fig. 1 is a view mainly in vertical central section of an apparatusconstructed in accordance with the invention; and

Fig. 2 is a similar view in vertical central section of a modified formof apparatus.

Referring now to the drawing and particularly to Fig. 1, 1 denotes avessel for holding l quefied gas, the outer wall of which, somet1mesdesignated a pressure vessel, is made sufliciently strong to resistrelatively high internal pressures; the vessel having a relatively longnarrow neck 3. Within the vessel 1 is preferably disposed an innerreceptacle or basket 4 which is made of a suitable ductile metal, forexample tin, is relatively thin and is spaced from the inner surface ofthe vessel 1 to provide a relatively narrow chamber or gas space aboutthe receptacle in order to reduce the amount of heat that wouldotherwise pass thereto. The receptacle 4 is open at the top so as tocommunicate with the gas space; care being taken when filling thereceptacle with liquid to avoid any overflowof liquid into the gas sace. By this arrangemenbit is seen that t e pressures on the two sidesof the wall of the receptacle are always substantially in equilibriumand strain in the thin metal of the wall of the receptacle avoided.

The vessel 1 is enclosed within and supported in spaced relation to thewalls of a casing 8 that has a base 19 and a cover 14:; the.

latter being shown as frusto-conical in form. The space between thevessel and the walls of casing 8 is substantially filled with a suitable non-combustible insulating material, for example slag wool orinfusorial earth, in order to provide an insulating envelope for theliquid holding vessel.

A filling and withdrawal tube 7 is passed through the wall of the vessel1 and extends to a point near the bottom of receptacle 4:. For fillingpurposes this tube-has a branch pipe or tube 2, which is preferablypassed directly through the cover 14 and is arranged to be connected toa source of liquid supply (not shown in the interests of clearness). Avalve 13 is provided to control the passage of liquid through the pipe2, which may be coiled about the neck 3 of the vessel 1 in order toeffect heat exchange between the gas in neck 3 and the liquid whenpassing in pipe 2. A controlled by-pass connection 12 is A second branchpipe or tube for with-.

drawal purposes is also arranged to commu- "iicate with tube 7. Thissecond branch pipe is here shown as a double coil 5-6 that is arrangedto have a portion leading from the top of tube 7 down over the side ofvessel 1 to a point near the base 19 from which point it again is ledupwardly in a series of convolutions having increasing diameters as thetop of the casing 8 1s approached, the convolutions at first beingdisposed close to the vessel 1. From the top, still within theinsulating space of easing 8, the coil descends in a second series ofconvolutions which have increasing diameters (with the exception of thelowermost turns) until a point near the bottom of the casing 8 isreached. From this point the coil is then led through the casing walland thence upwardly in a third series of convolutions secured on theoutside of the casing 8. The outer end of this coil communicates at 9with a gas withdrawal conduit 10, leading from the neck 3 and providedwith a discharge control valve 11; the outside portion of neck 3 beingpreferably arranged to minimize the conduction of heat to the vessel 1as far as practical and in consequence is shown as having a separableportion secured in place by means of a stuffing box 15 on the crown ofcover 14 and provided withaventvalve 20. In addition to the stufiing box15, the casing 8 has its other joints preferably made airtight andaccordingly is shown with packings 16, 17 and 18 inserted at the jointsin the manner illustrated.

The gas withdrawal conduit is adapted to supply gas directly to aconsuming device at any desired pressure, the pressure had depending ofcourse on the adjustment of the I valve 11. As the rate of gaswithdrawal from the conduit 10 may at times exceed that at which gas isevolved from the vessel 1, it is desirable to have a supply of gas underrelatively high pressure in reserve. This is accomplished by providing agas receiver or cylinder B having a pipe connection 44 leading to theconduit 10 from which it is filled when the gas demand is nil or lessthan the rate at which gas is evolved in the container ofthe presentinvention. To permit the receiver B being conveniently filled when thegas demand is nil and the valve 11 closed, a valved by-pass ispreferably provided, as shown at 43, connecting pipe 44 with conduit 10.The receiver B may also have an independent valved outlet, as shown at45, at itslower end.

The operation of the liquid containing apparatus above described is asfollows: Liquefied gas is first introduced to the vessel 1 by theconduit means 2 and 7. The gas which is evolved during the fillingprocess is first.

filling operation. During this filling operation, the by-pass at 12 maybe opened to convey the gas evolved during the initial cooling of thefilling means. The normal withdrawal of gas from the container hereprovided may be had either through the neck 3 from the gas space abovethe liquid in vessel 1, or from vaporization of liquid with- .drawnthrough the coil 5-6;

If it is desired to withdraw gas from the coil, communication betweenpipe 10 and the gas space above the liquid level is shut off so thatthere is produced an excess pressure in the vessel, at the end of thecoil within the vessel 1. In this manner the liquid is driven into thecoil under pressure so that upon withdrawal of gas from the coil throughpipes 9 and 10 the liquid contents of the vessel are forced into thecoil to take the placev of the gas removed therefrom. The evaporation ofthe liquid is not in excess of the quantity of gas removed. If it isdesired to draw oil from the space above the liquid level, this gasspace is opened to communication with the pipe conduit 10. At this time,although the coil enters the consumption conduit at 9, nevertheless noliquid will evaporate from the coil, for the reason that the pressure onthe liquid in the vessel is the same as that on the liquid in the coil.This pressure equalization takes place at 9.

In this connection, it may be stated that the coil may be constructed ofany desired length and may also be of any definite diameter. Theseconstructional dimensions depend upon the character of the liquid to begasified. For instance, the evaporation heat required for methane isabout 2% times as great as that for oxygen. It follows, therefore, thatit would be necessary to make the coil for the gasification of methanelonger, from point to point, in the vessel, than for oxygen.

It will be seen that the arrangement of the coil 5--6 in the insulatingspace about the vessel 1, in which the inner turns are in closeproximity to the vessel,'.while the outer turns progressively increasetheir diameter as they-approach the casing 8, is such as to utilize theheating effect of the insulating envelope. It will be perceived thatthere is a more or less constant How of heat in the insulating envelopefrom the outside of easing. 8 to the outer wall of the vessel 1. Suchheat as the insulating envelope contains may, therefore, be absorbed bythe liquid withdrawn through the coil 56 as it progressiveevolution ofgas.

While the withdrawal of cold gas mate rial from the vessel 1 involvesheating 1n order to supply the same as compressed gas at a predetermineddesired pressure, in the apparatus shown in Fig. 1, which involvesdissipating the refrigerating effect in.t1ally obtained by the processof liquefaction, 1t 1s contemplated conserving this effect in certainforms of practicing the present invention, the containing apparatus forthe liquefied gas in such instances being modified to conserve therefrigerating effect by means of heat exchangers associated with thewithdrawal conduits. An arrangement for carrying out this form of theinvention is shown in the apparatus illustrated in Fig. 2.

In Fig. 2, the apparatus illustrated employs a vessel 1 having arestricted neck 3 supported and surrounded by a casing 8, having theintervening space substantially filled with insulating material, whichconstruction ma be substantially the same as that disclose in Fig. 1,with the exception that a by-pass 21 is shown for providingcommunication between the neck 3 and the gas space about the receptacle4, the by-pass being controlled by a valve 22 actuated from without bythe stem 23 and hand wheel 24; the filling and withdrawal meanscomprising conduits 2, 7, and coils 5-6 being also the same,'but arepartially omitted from illustration for the sake of clearness.

Supplementary gas withdrawal means are here provided in the form of aconduit 29 communicating at its inner end with the neck 3, as indicatedat 28, this conduit having successive portions disposed in theinsulating material so that the temperature rise therealong coincidesapproximately with the temperature increase in the insulating materialin substantially the same manner as described above in connection withcoil 56, the outer end of this conduit discharging into the conduit 10,and being provided with a flow control means here shown as a valve at30. The heat exchanging means associated with this supplementary gaswithdrawal conduit comprises a conduit 34, here shown as having asufficiently small diameter, to be disposed within the conduit 29 and totraverse the same along the axis thereof until a point is reached nearthe outer end of the conduit 29, from which the conduit 34 is led outindependently and provided with a valve 39 for controlling the ingressof compressed air or other gas thereto; the conduit 34 preferably havingby-pass communication with the conduit 40, which is here shown ascontrolled by a valve 36 actuated by a stem 37 and hand wheel 38.

In carrying out the further conservation of the refri erating effecthere desired, the inner end 0% the vessel 1 is shown leading to adistributor 41 of a rectifying column 25. This latter is 1 shown ashoused within the vessel 1 and provlded with the usual counter-currentcontacting means26 and an evaporator or kettle 27 in the/lower end,vaporization being effected in the kettle by a coiled portion of theconduit 34, which is preferably made to ass therethrough, thedischargepf fluid rom the coil 34 through the distributor 41 beingpreferably controlled by valve 33, shown as actuated by stem 32 and handwheel 31. The non-condensable constituents of the products of'rectification within the column 25 are withdrawn through a conduit 40,which is passed through the top of the vessel 1 and also arranged inheat exchanging relation with the supplemental withdrawal conduit 29.

The conduit 40 is of relatively largediameter and is preferably arrangedto envelope the conduit 29, following the same to a point on the outsideof the casing 8 where exit of the withdrawn products is controlled by avalve 42. The rectified product which collects in the bottom of thecolumn 25 may be passed directly into the vessel 1 through a suiiableoutlet from the column here shown at. 6.

The operation of this modified form of apparatus is the same as thatshown in Fig. 1, except as the use of the triple conduit system 29, 34,40 and the rectifying column 25 are involved. When compressed gas iswithdrawn through the conduit 29, the refrigerating effect of this gasis conserved by admitting compressed gas to the conduit 34, which isaccomplished by opening the valve 39. The compressed gas being withdrawnin order to supply a consuming device, is passed in heat exchangingrelation with the warm gas entering through the conduit 34, so that therefrigerating effect of the cold gases initially passing out through theconduit 29 has been substantially transferred to the gas entering therectifying column 25. Here, a further refrigerating effect is practicedin the rectifying column, so that a liquefied product such as liquidoxygen is supplied to the vessel 1. The conduit 40 serves as the meansfor drawing ofi' nitrogen and other uncondensable gases from the column25, and follows the conduit 29, so as to transfer its refrigeratingeffect to the gas material entering the rectifying column 25. By openingthe by-pass valve at 36 and closing the valve 33, the rectifying columnmay be shortcircuited by way ofthe by-pass, whereupon the gas materialsupplied by the conduit34 will pass directly into the conduit 40,thereby increasing the rate of evaporation.

the conduit 34 depending into phase, a liquid phase Having described myinvention, what I claim as new and desire to secure by Letters Patent,is:

1. Apparatus for the production of pres "sure gases of differentadjustable pressures coil of which the vaporized gas flows, forprecooling another medium in the inner coil thereby to assist inliquefying said medium.

2. Apparatus for supplying gas material in the gas phase converted fromliquefied gas, comprising an insulated container for the liquefied gas,a receiver for gas in the gas phase, a gas phase withdrawal conduitleading from said container to a consuming device, flow controllingmeans in said conduit, a liquid phase withdrawal conduit leading fromsaid container and communicating with said first named conduit inadvance of said flow controlling means, and a, connection leading fromsaid receiver to said conduit for supplging gas conserved from saidcontainer.

3. pparatus for supplying gas material in the gas phase converted fromliquefied gas, comprising an insulated container for the liquefied gas,a receiver for gas in the gas phase, a liquid phase withdrawal conduitleading from said container to a consuming device. heating means in saidconduit, flow controlling means in said conduit adjacent said heatingmeans, a gas phase withdrawal conduit connected to said first namedconduit in advance of said flow controlling means, and a connectionleading from said receiver to said conduit for supplying gas conservedfrom said container. s

a. Apparatus for supplying gas material in the gas phase converted fromliquefied gas, comprising an insulated container for the liquefied gas,a receiver for gas in the gas withdrawal conduit leading from saidcontainer to a consuming device. heating means in said conduit, flowcontrolling means in said conduit following said heating means, a gasphase withdrawal conduit including additional flow controlling meanscommunicating with said first named conduit between said heating meansand said first named flow controlling means, and a connection leadingfrom said receiver to said conduit for supplying gas conserved from saidcontainer. 7

5. Apparatus for supplying gas material in the gas phase converted fromliquefied gas, comprising an insulated container for the liquefied gas,a receiver for gas in the gas phase, a liquid phase withdrawal conduitleading from said container to a consuming device, heating means in saidconduit, flow controlling means in said conduit followin said heatingmeans, a gas phase withdrawa conduit communicating with said first namedconduit at a point in advance of said flow controlling means, and aconnection leading from said receiver to said conduit communieating at apoint in advance of said flow controlling means.

6. Apparatus for supplying gas material in the gas phase converted fromliquefied gas, comprising an insulated container for the liquefied gas,a receiver for gas in the gas phase, a liquid phase withdrawal conduitleading from said container to a consuming device, heating means in saidconduit, flow controlling means in said conduit following said heatingmeans, a gas phase withdrawalconduit including addition a1 flowcontrolling neans communicating with said first named onduit betweensaid heating means and said first named flow controlling means, and aconnection leading from said receiver to said conduit also provided withflow controlling means and communicating with said first named conduitat a point in advance of said first named flow controllin means.

In testimony whereof I a x my signature.

' CHRlfiTlAN WlLl'lELM PAUL HEYILANDT.

